Ruling · Rādhāṣṭamī · 1966

Wednesday 21 September

Determinatein Tehran, under the Rashtriya Panchang method. Clear of every threshold by 323 minutes.

Decide it for

TehranDelhiKolkataSingaporeSydneyJersey City

35°42′ N 51°25′ E · Asia/Tehran · GeoNames 112931

The two middays

One ghaṭī is 24 minutes. Madhyāhna is 1 ghaṭikā either side of midday.

Midday of Wednesday 21 September

Taken. The only midday Aṣṭamī reaches.

madhyāhna begins 11:33  12:21 madhyāhna ends
10:4511:0911:3311:5712:2112:4513:09

48 of 48 minutes covered

Midday of Thursday 22 September

Aṣṭamī is absent from madhyāhna. Not taken.

madhyāhna begins 11:33  12:21 madhyāhna ends
10:4511:0911:3311:5712:2112:4513:09

0 of 48 minutes covered

Aṣṭamī presentMadhyāhna, the window the rule readsThe instant the tithi begins or ends

How it was decided

  1. 01

    Aṅga

    Aṣṭamī runs from 05:50 on Wed 21 Sep to 06:10 on Thu 22 Sep.

    1966-09-21T02:20:22Z → 1966-09-22T02:39:34Z

  2. 02

    Kāla

    Madhyāhna is 1 ghaṭikā either side of midday: 11:33–12:21 on the 21st, 11:33–12:21 on the 22nd.

    madhyahna: midday-pm-1-ghatika · sunrise and sunset: upper limb, 31′ + 16′

  3. 03

    Rule

    Aṣṭamī must be present during madhyāhna. It covers 48 of 48 minutes on the 21st and 0 of 48 on the 22nd.

    Calendar Reform Committee 1955, General Rules for Religious Festivals, p. 103

  4. 04

    Tie-break

    Only one midday qualifies. No tie-break is needed.

    priority: unstated → only-day · margin 19402 s

  5. 05

    Ruling

    Rādhāṣṭamī, Tehran, 1966: Wednesday 21 September.

    confidence: determinate

Say it like this

In Tehran, Rādhāṣṭamī 1966 falls on Wednesday 21 September. Aṣṭamī runs from 05:50 on Wed 21 Sep to 06:10 on Thu 22 Sep and covers all of madhyāhna that midday.

ahargana.org/tehran/festivals/1966/radhashtami · pac-rp@2026.1

Who says what

AuthorityKindDate
Ahargaṇa, pac-rpThis rulingWed 21 Sep
Ahargaṇa, classicalDisc centre, no refractionWed 21 Sep
compat-drikpanchangComparison profileWed 21 Sep
No institution has a recorded ruling for Tehran.

Institutional rulings are recorded with a source address, and are never edited to agree.

The rule, as data

/rules/radhashtami · ruleset 2026.3-draft

Month
Bhādrapada, amānta
Pakṣa · aṅga
Śukla · Aṣṭamī
Kāla
Madhyāhna
Priority
Unstated
Tie-break
Longer coverage, as a boundary
Reference
CRC 1955, p. 103

“S 8 Durvastami (purvaviddha — S 8 of saura Bhadra except Bengal), Mahalaksmi vratarambha, Radhastami (madhyahna vyapini)” Calendar Reform Committee 1955, General Rules for Religious Festivals, p. 103.

The same rule, elsewhere

Twelve places, west to east. Local clock times.

PlaceAṣṭamīMadhyāhna 21stCoveredMadhyāhna 22ndCoveredRuled
Los Angeles19:20 → 19:4012:2248 min12:210 min21 Sep
Chicago21:20 → 21:4012:1948 min12:190 min21 Sep
Jersey City22:20 → 22:4012:2548 min12:250 min21 Sep
Port of Spain22:20 → 22:4011:3548 min11:350 min21 Sep
London03:20 → 03:4012:2948 min12:290 min21 Sep
Durban04:20 → 04:4011:2548 min11:250 min21 Sep
Dubai06:20 → 06:4011:4848 min11:470 min21 Sep
Delhi07:50 → 08:1011:5048 min11:500 min21 Sep
Kolkata07:50 → 08:1011:0648 min11:050 min21 Sep
Singapore09:50 → 10:1012:0448 min12:040 min21 Sep
Sydney12:20 → 12:4011:250 min11:2448 min22 Sep
Suva14:20 → 14:4011:360 min11:3548 min22 Sep
Profile · tradition
pac-rp@2026.1 · smarta
Rule
radhashtami@2026.3-draft
Engine · kernel
0.1.0 · de440 7eef…ea74
Boundary margin
300 s

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